Harris E F, Hicks J D
Department of Orthodontics, College of Dentistry, University of Tennessee, Memphis 38163, USA.
Arch Oral Biol. 1998 Oct;43(10):825-31. doi: 10.1016/s0003-9969(98)00061-2.
Crown sizes of human teeth are sexually dimorphic, with male larger than female. This holds for most human groups, though the extent of dimorphism varies among populations. It is not known whether size dimorphism is due to differences in enamel thickness, dentine differences, or some combination of the two. This study examined the pattern of variation in enamel thickness on the mesial and distal margins of the four maxillary permanent incisors. Standardized periapical radiographs of the incisors of 115 adolescent American whites were measured. Enamel was significantly thicker on the distal than the mesial margins of both the lateral and central incisors, with a mean difference of 0.1 mm. There was no sexual dimorphism in the maximum mesial or distal enamel thicknesses. In contrast, the widths of the dentine of the crowns were significantly greater in males, by an average of 6.5%. Sexual dimorphism in mesiodistal diameters of the incisors seems, then, to be due to the dentine component, which is the size attained at the end of the bell stage of tooth formation. Sex-specific correlations between enamel thickness and crown width of the dentine were low (and lower for males), indicating considerable independence between regulatory mechanisms of dentine and enamel development.
人类牙齿的冠部大小存在性别差异，男性大于女性。这在大多数人类群体中都成立，尽管不同人群中这种差异的程度有所不同。目前尚不清楚大小差异是由于釉质厚度的差异、牙本质的差异，还是两者的某种组合。本研究检查了上颌四颗恒牙切牙近中边缘和远中边缘釉质厚度的变化模式。对115名美国白人青少年切牙的标准化根尖片进行了测量。侧切牙和中切牙的远中边缘釉质明显比近中边缘厚，平均差异为0.1毫米。近中或远中最大釉质厚度不存在性别差异。相比之下，男性牙冠牙本质的宽度明显更大，平均大6.5%。因此，切牙近远中径的性别差异似乎是由于牙本质成分，这是牙齿形成钟状期末达到的大小。釉质厚度与牙本质冠宽之间的性别特异性相关性较低（男性更低），表明牙本质和釉质发育调节机制之间具有相当大的独立性。
